X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=path.c;h=334b2bd195f56ac6aaf9f9b8a36fe59115cd758c;hb=74237d6236d7e32f69469ff26df3f3bb3875f523;hp=2c077c0c8f7066c5338050ce890c0846adedf6bd;hpb=069b20a198f171512a1d2d2163b40f70c94f5257;p=git.git

diff --git a/path.c b/path.c
index 2c077c0c..334b2bd1 100644
--- a/path.c
+++ b/path.c
@@ -131,76 +131,121 @@ int validate_symref(const char *path)
 	return -1;
 }
 
-static char *current_dir(void)
+static char *user_path(char *buf, char *path, int sz)
 {
-	return getcwd(pathname, sizeof(pathname));
-}
-
-static int user_chdir(char *path)
-{
-	char *dir = path;
+	struct passwd *pw;
+	char *slash;
+	int len, baselen;
 
-	if(*dir == '~') {		/* user-relative path */
-		struct passwd *pw;
-		char *slash = strchr(dir, '/');
-
-		dir++;
-		/* '~/' and '~' (no slash) means users own home-dir */
-		if(!*dir || *dir == '/')
-			pw = getpwuid(getuid());
-		else {
-			if (slash) {
-				*slash = '\0';
-				pw = getpwnam(dir);
-				*slash = '/';
-			}
-			else
-				pw = getpwnam(dir);
+	if (!path || path[0] != '~')
+		return NULL;
+	path++;
+	slash = strchr(path, '/');
+	if (path[0] == '/' || !path[0]) {
+		pw = getpwuid(getuid());
+	}
+	else {
+		if (slash) {
+			*slash = 0;
+			pw = getpwnam(path);
+			*slash = '/';
 		}
-
-		/* make sure we got something back that we can chdir() to */
-		if(!pw || chdir(pw->pw_dir) < 0)
-			return -1;
-
-		if(!slash || !slash[1]) /* no path following username */
-			return 0;
-
-		dir = slash + 1;
+		else
+			pw = getpwnam(path);
 	}
-
-	/* ~foo/path/to/repo is now path/to/repo and we're in foo's homedir */
-	if(chdir(dir) < 0)
-		return -1;
-
-	return 0;
+	if (!pw || !pw->pw_dir || sz <= strlen(pw->pw_dir))
+		return NULL;
+	baselen = strlen(pw->pw_dir);
+	memcpy(buf, pw->pw_dir, baselen);
+	while ((1 < baselen) && (buf[baselen-1] == '/')) {
+		buf[baselen-1] = 0;
+		baselen--;
+	}
+	if (slash && slash[1]) {
+		len = strlen(slash);
+		if (sz <= baselen + len)
+			return NULL;
+		memcpy(buf + baselen, slash, len + 1);
+	}
+	return buf;
 }
 
+/*
+ * First, one directory to try is determined by the following algorithm.
+ *
+ * (0) If "strict" is given, the path is used as given and no DWIM is
+ *     done. Otherwise:
+ * (1) "~/path" to mean path under the running user's home directory;
+ * (2) "~user/path" to mean path under named user's home directory;
+ * (3) "relative/path" to mean cwd relative directory; or
+ * (4) "/absolute/path" to mean absolute directory.
+ *
+ * Unless "strict" is given, we try access() for existence of "%s.git/.git",
+ * "%s/.git", "%s.git", "%s" in this order.  The first one that exists is
+ * what we try.
+ *
+ * Second, we try chdir() to that.  Upon failure, we return NULL.
+ *
+ * Then, we try if the current directory is a valid git repository.
+ * Upon failure, we return NULL.
+ *
+ * If all goes well, we return the directory we used to chdir() (but
+ * before ~user is expanded), avoiding getcwd() resolving symbolic
+ * links.  User relative paths are also returned as they are given,
+ * except DWIM suffixing.
+ */
 char *enter_repo(char *path, int strict)
 {
-	if(!path)
+	static char used_path[PATH_MAX];
+	static char validated_path[PATH_MAX];
+
+	if (!path)
 		return NULL;
 
-	if (strict) {
-		if (chdir(path) < 0)
+	if (!strict) {
+		static const char *suffix[] = {
+			".git/.git", "/.git", ".git", "", NULL,
+		};
+		int len = strlen(path);
+		int i;
+		while ((1 < len) && (path[len-1] == '/')) {
+			path[len-1] = 0;
+			len--;
+		}
+		if (PATH_MAX <= len)
 			return NULL;
-	}
-	else {
-		if (!*path)
-			; /* happy -- no chdir */
-		else if (!user_chdir(path))
-			; /* happy -- as given */
-		else if (!user_chdir(mkpath("%s.git", path)))
-			; /* happy -- uemacs --> uemacs.git */
-		else
+		if (path[0] == '~') {
+			if (!user_path(used_path, path, PATH_MAX))
+				return NULL;
+			strcpy(validated_path, path);
+			path = used_path;
+		}
+		else if (PATH_MAX - 10 < len)
+			return NULL;
+		else {
+			path = strcpy(used_path, path);
+			strcpy(validated_path, path);
+		}
+		len = strlen(path);
+		for (i = 0; suffix[i]; i++) {
+			strcpy(path + len, suffix[i]);
+			if (!access(path, F_OK)) {
+				strcat(validated_path, suffix[i]);
+				break;
+			}
+		}
+		if (!suffix[i] || chdir(path))
 			return NULL;
-		(void)chdir(".git");
+		path = validated_path;
 	}
+	else if (chdir(path))
+		return NULL;
 
-	if(access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
-	   validate_symref("HEAD") == 0) {
+	if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
+	    validate_symref("HEAD") == 0) {
 		putenv("GIT_DIR=.");
 		check_repository_format();
-		return current_dir();
+		return path;
 	}
 
 	return NULL;